Afghan children on a long and perilous journey

The following is a script from "A Long and Dangerous Journey" which aired on May 19, 2013. Anderson Cooper is the correspondent. Ira Rosen and Gabrielle Schonder, producers.

In the 12 years American forces have been fighting in Afghanistan, we've learned a lot about the war, but we haven't seen much about what life is like for ordinary Afghans. The violence, the poverty, and the fear of the Taliban.

About a year ago we began to hear stories of a massive migration out of Afghanistan: a journey being made by thousands of Afghan children, some as young as nine years old. They often spend years on the road, trying to make it to Europe. To get there however, they have to survive what might be one of the most difficult and dangerous journeys in the world.

You see them all over Europe; small groups of Afghan boys, searching for a better life. Tired and hungry, these Afghan kids are on a Greek island trying to find a bus to Athens, just one more stop on a journey that's already taken some of them years. Police find them hidden under floorboards in vans or smuggled in secret compartments in trucks. Kids fleeing Afghanistan now make up one of the largest migrations of children in modern times.

Starting in Afghanistan the boys go through Pakistan, Iran, then Turkey and Greece and onward to countries throughout Europe. What can be a 10,000-mile journey across six mountain ranges and two seas.

Over the past year we've interviewed dozens of Afghan boys at various stages of their journey. Though they come from all over Afghanistan, their stories of why they're leaving are strikingly similar.

Hayat: In Afghanistan, there are all bullets, guns, people used to kill people for no reason.

Tavab: I couldn't follow my dreams there.

Hamed: I didn't have any future. Any future.

Ali Hassan: We are not safe in Afghanistan. You know the condition. It is always there is a killing, bomb blastings.

Ali Hassan's father was killed in Afghanistan. He fled with his two sisters and brother when he was just 11 to Iran, where he began working in a market.

Ali Hassan: We go from Pakistan to Iran illegally, me, my two sister, and my small brother.

He worked for two months in Iran, until the day he found out his siblings were caught by authorities and deported.

Ali Hassan: My neighbors, they told me that police came here and took your family and they deport to Afghanistan because we don't have any paper. So I'm nervous. I'm crying.

Anderson Cooper: You didn't know where they had been sent?

Ali Hassan: I don't know anything.

Ali Hassan: I was thinking if I go to Europe. Maybe one day I will find my family, and I will bring them here, and we will live a better life.

Ali Hassan: If a person lives with his family it's the best life ever, if a person lives lonely like me, like other boys, it's too difficult.

He says an Iranian man he worked for in the market paid a smuggler to bring him to Europe. The journey would take four years. At one point he was hidden in a refrigerated truck.

Ali Hassan: We are in freezer. Freezer. Two days, two night and four hours, I was in container. After 52 hours, I'm totally freezed. I can't shake my hand, my foot. On that time also I was think that maybe I will die.